On July 23, Chicago City Council passed a Building Energy Use Benchmarking Ordinance, requiring non-industrial buildings larger than 50,000 square feet to report their energy usage.

Less than one percent of Chicago’s buildings meet that threshold, but the 3,500 that do account for 22 percent of the city’s total energy use by buildings. If all municipal, commercial, and residential properties that large reduced their energy use by five percent, the city estimated it would save $40 million each year in energy costs, and reduce greenhouse gas emissions by an amount equivalent to removing 50,000 cars from the road. Buildings account for more than 40 percent of total U.S. energy consumption.

Reporting and disclosure deadlines will phase-in over a four-year period, with residential buildings given an additional year to comply. The ordinance requires relevant buildings to track, verify, and report energy consumption using the Environmental Protection Agency’s free, online ENERGY STAR Portfolio Manager.

After a one-year lead to allow buildings time for efficiency measures, the ordinance authorizes the city to share buildings’ energy use with the public. But the Building Owners and Managers Association (BOMA) of Chicago said no matter how it is phased in, public energy-use disclosure presents an unfair burden to some of the city’s landlords.

“[It] will unfairly penalize and marginalize many older and historically significant buildings in Chicago,” BOMA said in a statement. “Publishing the scores for buildings that simply cannot afford the work necessary to raise them will not shame those buildings into achieving higher scores. It will simply impose yet another competitive burden on an already challenged sector.”

Buildings larger than 50,000 square feet can be excused from the proposed ordinance if they are experiencing financial distress. The city’s chief sustainability coordinator, Karen Weigert, said that includes buildings occupied for less than half of the year, those in property tax arrearages, those controlled by a court appointed receiver, and those acquired by a deed in lieu of foreclosure.

According to BOMA’s 2012 Economic Impact Study, Chicago already ranks first in square footage of LEED certified existing buildings and LEED certified new construction, and it ranks second in square footage of office buildings with Energy Star ratings across all U.S. cities. Eight U.S. cities and two states currently have some form of benchmarking and disclosure ordinance. Last year, Chicago announced plans to cut energy use by 20 percent in large non-residential buildings within five years.